In large data network environments, it is important to be able to obtain statistics about the performance of input/output (I/O) operations on the physical network, such as the links which connected ports of different network devices. Statistics of interest can include the number of I/O operations a link can handle (in operations per second); the bandwidth of a link (in megabytes (MB) per second); the average number of concurrent operations using a link during a time period; the average transfer length (in MB/operation); and the average link utilization per operation (in micro-seconds/operation).
Such statistics may be used in real time to trigger fault procedures if a large variance from a normal value indicates the existence of a possible problem. Statistics may also kept in a log to be referenced during normal maintenance or problem resolution. Typically, statistics may be calculated by a network server, such as an Enterprise Storage Server® (ESS) sold by IBM® and may be maintained by one or more attached host devices. However, due to the large number of links between components in a network, collecting data and sampling the collected data to compute statistics can consume a large amount of valuable network resources. Consequently, it is desirable to provide for more efficient data collection and statistic generation.
Moreover, each device port may include more than one link type, such as ECKD™ (extended count key data), PPRC (peer-to-peer remote copy), and SCSI (small computer system interface). Consequently, it is desirable to generate statistics on a link type basis to provide a higher level of detail than generating statistics only by port.